My memory doesn't serve me too well these days but I flew AS332L LN-OMI which had full de-icing and yes I believe there was a 3rd Alternator. If not a 3rd then beefed up 2 others. We also had a pneumatic leading edge on the horizontal stabilser which inflated and deflated sequentially which had a gentle but interesting attitude change. You would be flying along and the nose would go down a bit and you thought "well at least the stabilser boot is working!!".
Maybe those Norsk guys who worked out of Hammerfest could enlighten you more
John